Basis of Presentation and Significant Accounting Policies Basis of Presentation and Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Details) - USD ($)
$ in Thousands
Dec. 31, 2019
Oct. 01, 2019
Sep. 30, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Accumulated deficit $ (210,160)   $ (209,340)
Operating lease liability recognized upon ASU adoption $ 2,288    
Accounting Standards Update 2016-02      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Operating lease liability recognized upon ASU adoption   $ 2,600